How to extract the application brand logo image over an API?

When I checked in the app, the Ant deploy error was:

In field: logo - no ContentAsset named CV_CF_Icon_128 found

which a quick Google then revealed this new type name to be added to package.xml:

<types>
    <members>CV_CF_Icon_128</members>
    <name>ContentAsset</name>
</types>

that resulted in a folder called contentassets in the project with a CV_CF_Icon_128.asset file and a corresponding meta file of:

<?xml version="1.0" encoding="UTF-8"?>
<ContentAsset xmlns="http://soap.sforce.com/2006/04/metadata">
    <language>en_US</language>
    <masterLabel>CV_CF_Icon_128</masterLabel>
    <relationships>
        <organization>
            <access>VIEWER</access>
        </organization>
    </relationships>
    <versions>
        <version>
            <number>1</number>
            <pathOnClient>CV_CF_Icon_128.png</pathOnClient>
        </version>
    </versions>
</ContentAsset>

This deployed correctly in the next build.